It is known to use tape for masking of corners in connection to painting work, for instance for painting of walls, roofs, borders, door cases, window seats etc., with the purpose to prevent paint from coming into contact with surfaces which are not intended to be painted. In the preparation work before painting, it is common that corners, often having an angle of 90°, shall be masked, for instance the masking of a floor surface in a corner of the wall. A problem facing a painter aiming to mask a corner with masking tape is to successfully cover the entire surface to be masked since the masking tape in most cases are torn off and gets a non-perpendicular tear edge. A sloping or inclined tear edge can lead to that surfaces are exposed and get exposed for splash of paint which can lead to costly renovation work and delays in the work. At the same time, it can be a disadvantage or impossible to place masking tape pieces that are slightly too long in a corner as it is true that it covers for instance the entire floor surface corner, but, in such case, unfortunately also parts of the wall that is intended to be painted.
A number of attempts have been made to overcome the problem above. In the patent application US2010/0059162 A1 an embodiment is described comprising perpendicular or right-angled tape pieces having perforation axis between them which by an adhesive surface abut a backing paper which is rolled-up in a storage condition. In another embodiment the tape pieces have the shape of triangles which are arranged in a grid-pattern, have both adhesive and non-adhesive zones on the dorsal side and which are mounted adjacent on a backing paper which is rolled-up in a storage condition. The disadvantage of this solution is partly that the perforation creates a certain risk that the tear edge is not getting right-angled and thus functionable for the purpose of the first embodiment, partly that the arrangement of triangles according to a grid-pattern corresponds to an aggravated manufacturing process where only parts of the undersides or dorsal sides of the triangles shall be applied with adhesive. Further, a backing paper is used that increases the cost of manufacturing and the waste during use.
U.S. Pat. No. 3,752,304 concerns a masking aid means for masking of rectangular surfaces that enables painting of the peripheral edges thereof. The means comprises rectangles which are perforated and separable along a diagonal and thus form the hypotenuse of two triangular means. The rectangle can be used in its entirety or as individual rectangles and be adapted for the rectangular surface to be masked through making the hypotenuses overlap each other. On the back of each of the triangles there is adhesive comprised by removable adhesive strips. The masking aid means according to this description is intended for covering entire larger surfaces such as windows of different size and does not indicate how a large number of masking means can be manufactured and stored in a cost effective manner.